Injection molding machine



March 30, 1948. KNOWLES 2,438,856

INJECTION MOLDING MACHINE Filed Feb. 5, 1944 3 Sheets-Sheet 1 invenio r.-

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March 30, 1948. E. R. KNOWLES INJECTION MOLDING-MACHINE 3 Sheets-Sheet 2 lzzvenior: I Edwardfilfiwwics.

Filed Feb. 5, 1944 %z dl March 30, 1948. h K L 2,438,856

I NJEC'IION MOLDING MACHINE Filed Feb. 5, 1944 5 Sheets-Sheet 5 Patented Mar. 3.0, 1948 UNITED STATES PATENT OFFICE INJECTION MOLDING MACHINE Edward R. Knowles, Nashua, N. H.

Application February 5, 1944, Serial No. 521,171

1 Claim.

My present invention relates to the molding of plastic materials. Among its aims is to provide molding apparatus wherein various main elements are structurally adapted for different rela tive positioning and operative assembly to satisfy different manufacturing conditions and requirements. The invention further aims to provide in apparatus of the general class referred to various improvements contributing to the production of a wide range of molded articles of better and more uniform quality and also affording greater safety in operation, generally extending the useful range and life of the equipment and increasing its productive efficiency.

In the drawings illustrating by way of example certain embodiments of the invention and of means whereby the methods thereof may be practiced:

.Fig. 1 is a side elevation of a molding assembly wherein the several elements or units are disposed for generally horizontal operation of the dies and to which latter the molding material is presented laterally;

Fig. 2 is a similar elevation showing the corresponding machine units of Fig. 1 installed as for entering the molding material substantially centrally of horizontally operative dies; and

Fig. 3 is a corresponding elevation of the apparatus of Figs. 1 and 2 disposed for vertical operation of the dies and for lateral presentation of the molding material to them.

Referring to the drawings in more detail, and first in general to the apparatus as a whole and as seen-in the interchangeable installations of Figs. 1, 2 and 3,the same comprises several main elements, units or assemblies. These include a material feed and conditioning assemblyor injection unit A, and a molding unit or press B, for hydraulic or other operation. The injection unit A is mounted on a base or frame element indicated generally at 0, adapted to house the actuating and control system, the latter pref erably hydraulic and either self-contained or associated with an outside or central power source. The molding press B is supported jointly by this frame or housing C and a separable frame element indicated generally at D.

The material conditioning and injectionunit comprises in general a measuring and. feeding mechanism indicated as a whole by the numeral Ill and a charging head or cylinder designated generally at 23. The material to be molded, in granular or other form, is supplied from a hopper l l to a feed chamber H for delivery as at the port 13 arranged to present it to an inlet l4 admitting to the conditioning cylinder 20. Measured charges of the material are delivered from the feeding chamber l2 as by means of a, reciprocating feed rod IS. The latter is actuated in proper timed relation, herein through connections with a material charging plunger l6 provided with drive means illustrated as of the hydraulic type, comprising the cylinder 2| having appropriate control valves. In the illustrated example, the connections between the charging plunger and the feed rod include a two-arm lever l1 mounted for rocking action on a fixed part such as the bracket l8 and pivotally connected at its opposite ends with the feed rod and the charging plunger respectively.

Charges of the molding material are thus advanced into the conditioning cylinder 23 and discharged atthe nozzle 22 for injection into the mold space. The cylinder 20 desirably includes heating means and torpedo or other means, not necessary to show in detail here, for distributing and guiding the conditioned material to the nozzle. This injection cylinder may be similar to that as more fully disclosed and claimed in my copending application Serial No. 523,678, filed February 24, 1944, such unit or assembly A being here illustrated sufficiently for indicating its relation and general manner of assembly in combination with the apparatus as a whole. 7

Considering now the molding unit or press .8, seen in different assembled relations in Figs. 1, 2 and 3, the same comprises an outer stationary end plate or head 30 and an inner or opposite end plate and die holder 3 I. These are connected by a series of parallel rods 32, four of them in the present instance, provided at their respective endswith cap nuts 32a. The end plate 30 is mounted in firmly fixed position on a basal support, herein the frame unit D, as at 10, and is held against movement relative to the rods 32 by the anchoring nuts 32a. The end die-holder plate 3| is movably supported on the rods ,32, where itis held against outward movement by the adjacent end nuts 32a, which latter are turned up on the reduced threaded ends of the rods, against shoulders thereon.

Also slidably mounted on the bars 32 is the inner die-holder plate 33, adapted for advance toward and opening retraction from the end die plate 3|. These die plates 3|, 33 have at their opposed faces slots or like attaching means as at 34, 35 to receive mounting studs or like formations on the removable dies proper 36, 31, the

parting line of which is indicated at 38.

The inner holder plate 33- together with its on the fixed outer end plate 30 respectively.

Actuation of the toggle mechanism, and its links 41, 48 for advancing, holding closed and retracting the movable die elements is eifected as by means ofa =plunger; adapted toqbe driven=instheopposite directionsfbyipow'er applyingmeans such:

as the hydraulic cylinder 44 here shown by way of example. novel manner of operation is more fully described in my application Ser. No. 573,335; messen- 18 1945, entitled Plastics molding apparatusil. -a.. 5,.

division of the present application. Said divisional application may also 'be"refer-red' 'to fora detailed description of the knock-out mechanism herein generally referred to by numeral 90.

Referring .tdFig. 1,.thefour main assemblies or 20 ur'iits'are' th re shown-intheiroperativeerranee: merit f'c ifwhat. is'jherfe. termed ofis'et" or "overhead injection. Injsuchioperation' th'e'materialis de live'red to, the" dies. through an. orifice laterally spaced from. tHelo'hgitudiIIal "axis of thepress,

out. o'fflir'ie withzthediec'av'ity or cavities" trans= vrsely to the direction of, opening ahd"'.c1tising; Sii'ch'iarrangement-isparticularly suited formoldiiiggplat'e like' ari'd'oth'er parts, such fbrexample asntia'iisparent coversffor dials', gauges, clo'ck'sand thellili, where' the. mainifa'ce 'or" surfacearea deisirablyv is clear of." disfiguringv irregularities, as likelirto result from remo val"ofjspurs; sprue slugs or other superfluousma't'erialf there-at." Accordingly. the dies proper 36, 31Tareformedwitli lateral 35 extensions 3fia,..3'l'a' into which'theJ sprue; gate, onoth'er passages are extended from" the mold cayity' or. cavities and into communicationiwith anpffset or overhead external orificeforseatin'g the;nozzlelzi'and.for'entry of th'e moldingmate= 40 rial delivered-by 'theilatte'r;

T6, present the injectionunitl'A with its co'n'di tio'ningcylinder 201 and nozzle 22" inipjrop'efalignmentfwi-thi such offset injectionorifice; the main frameor base unit, C i's; equipped with a" detachiable .t'opj extension. or table proportimed and arranged; for removable, seating" on th'efr'am'e' C and of a height to disposethe injection" unit' A at .the.,.desired level.- This table" 50"" is" formed at its lower'poftioniwitha plurality of feetor like 50 attaching i'or irl'ati'o'ns 5T, herein atrear','.interm'e=- diaIte and forwardlocations,. for'reception by corresponding. .sea'ting. formations 52; 52", 5211' on'ithe Id'aseflC; where, they are demountably fi'xed'asby beltsorotheriwise. Similarly; at'its upptr'portibn the=table-.5Bl has rear and" intermediate seats 53 forl'atera/l 'bossesorfeet 54" at the lower'pj'o'rtion'o'f theinjection unit A, Further, attaching means includesatf the. inner or. forward endofth'eta'bl'e 5ill.a','.,guide pl'ate iii' having a longitudinal guide 0 .slotfor, reception of a slide block"56 secured to the.,.conditi'oning cylinder 2'0";v afibrdingi capacity for longitudinal adjustment of thelatter, in a manner .asmore' fully described in mycopendin'g Inr this F-i'g. ,1 assembly of the several units, for the=.describedoverhead .or offset injection operations; the press unit1.B is disposed for operation inga.horizontallplane; as' also in the Fig. 2'ar- 7'0? non-threaded end portion 3221: of each rod 32. 75

This toggle mechanism and then At its other end the press unit B is fixedly supported on the adjacent underlying portion of the demountable frame extension unit D, through the medium of detachable anchor means as indicated at Ill. This frame element D is removably at- When disassociated from the frame 0 it desirably V has a supporting leg or upright 12 at its inner portiomserving also as further bracing means for .thelpressiunitlB.

Fig. illustrates a further manner of assembly ofithesiourrmainiunits A to D, again for injection operations in a general horizontalplane, but in th'isinstance with the elongated injection nozzle 22a extended through a'bore 3m provided therefor in i the inner" end die plate 3 and i through which tlie' n'ozzle'i's applied- 111 lin with" thepath ofthe movable die 3 In this installation the extension table' 50 of'Fi'g; 1 is demo'unted an'd the injection unit A as 'a whole-installed directly? at the top of' the mainframe CI For'thispurpose the supporting-feet "54 0? the 'unit'A and the seats 52 onthe framefi are so" spaced and'arranged as to-come opposite each other in proper seating relation in the assemblyasin Fig. 2, for in-line injection. Similarly, the previously mentioned forward seat 526 .of 'frame Cisformed as a slotted guide member corresponding: to the guide I 55 of Fig. 1, for-adjustable reception-of the-foot 56 of the injection uniti In other words, the series of attaching'formations 52;"52aof the base C and the members-53 55 'of'the extension table 5001' Fig. 1 are selectively available for attachment' of the injection-unit Otherwise thanas stated the general arrangement and interconnection of the several units B; C 'andD maybe-the same in Fig; Z' 'as in connection' with I the set-up Ias illustrated in Fig. 1.

ReferrihgnowtoFi'g. 3, a still further arrangement of tl'i'e several units is there shown, in which the pressunit B' is-di'sp'osed for operation in the vertical plane'. Inthis case'the-relation andman ner of attachment as between the injection unit A and the mainframe C may be the same as in Figa '25 The-lateral frame or base D of' Figs; 1 and 2 is here substitutedby-a similar but'shorter frame unit D'"havingsimilarprovision at its-inner portion for detachably securing it; as at H"" to theadja'cent portion of the frame 0, and also'hav in'gindep'endent orself-supporting means 12 as for'unit Dof Figs. 1 and 2'. The upper portion of this alternative frame D is formed with appropri'ately spaced apertures for reception of the lower ends of the now' vertical supporting rods 32 ofthe press- B; The latter as a wholemay be readily installed on the frame D by removing the anchor'nuts 32a, setting the endsof the bars' 32 down through" said receiving apertures of the H frame: andthen replacing the nuts, substantially application Serial No. 5231678 previously. men- 65 tioned.-.-

as in Fig: 3;, ,The'press unit may be additionally braced and anchored as bymeans of a bracket 13 secured .atits outer end to the adjacent face of the now'lower and stationary'die plate 3|, and at its innerportion fixed upon a seat 63 on the frame Cwhich forms a portion of the expansion bearing 60 previously mentioned in connection with Figs. 1 and 2;

In this Fig. 3 installationzthe. apparatus as a whole maybe employed for the practiceof the novel molding method" as disclosed and claimed in my earlier copending application Serial No; 503,360, filed Sept. 22, 1943, upon installation of certain means as comprised in the apparatus of said invention and application and for which the press unit B and its supporting means are herein adapted; or it may be utilized for molding operations of the usual or standard type.

Accordingly the end die plate 3| which has become the bottom end member in this vertical installation has attached at its underface an hydraulic cylinder 8!! having a ram 8! in line with the stem 82 of a presser head or force 83. The latter is movably positioned and guided in a chamber provided for the purpose in the bottom die 36 which is of the spiral construction and arrangement for cooperation with this force or compressive die element 83, as more fully disclosed and claimed in my copending application Serial No. 503,360 previously mentioned. It will be noted that the stem 82 of this force element 83 is re ceived and guided in the same through aperture 3la of the die-holder plate 3| which in the Fig. 2 installation is employed for entry of the elongated nozzle 22a.

For standard molding operations the lower hydraulic cylinder 80, Fig. 3, together with the associated force element 82, 83 may be omitted, in which case the aperture am in the end plate 31 may be closed as by a removable insert 3"), the latter also being employed in connection with the oifset injection operations of the Fig. 1 installation.

Having disclosed a preferred embodiment of my invention, what I claim is:

Plastics molding apparatus comprising, in combination, aplurality of assembly units mutually 6 adapted for installation in different selected operative relations, said units including a material feeding, conditioning and injecting unit provided with spaced mounting and securing formations along its under surface, a main base unit adapted to house actuating and control means for the apparatus, an auxiliary support attached to said main base unit, a molding press mounted on said auxiliary support and adapted to secure moldin die parts in operative relation to said injecting unit, mounting and securing formations on said main base unit complementary to those on said injection unit and having identical spacing; and a demountable top extension disposed horizontally between said units and provided with upper and lower mounting and securing formations complementary respectively to those on said injection unit and on said main base unit, the upper mounting and securing formations on said extension being displaced laterally from the lower formations thereof, whereby said injecting unit may be secured directly to said main base unit in one lateral relationship, or indirectly through the intermediary of said extension at a higher level and in a different lateral relationship.

EDWARD R. KNOWLES.

REFERENCES crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,293,304 Muller et a1 Aug. 18, 1942 2,309,460 Lester Jan. 26, 1943 2,333,056 Thoreson et al. Oct. 26, 1943 

